The disclosure relates to a multiphase power factor improvement circuit such as an interleaved converter.
Japanese Patent Application Publication No. 2013-192340 discloses a continuous conduction mode power factor correction (CCMPFC) circuit. This circuit detects an inputted current and performs power factor correction control based on the detected inputted current.
Japanese Patent Application Publication No. 2014-68424 discloses a CCMPFC circuit. This circuit detects a switch current flowing through a switch and performs overcurrent protection for the switch based on the switch current.
FIG. 6 illustrates a single-phase CCMPFC circuit. In this circuit, a ground current detected by current sensor S3 is equal to an inputted current (current flowing through reactor L1) necessary for CCMPFC control. Besides, while switching circuit Q1 is ON, the ground current is equal to the current of switching circuit Q1. For this reason, it is possible to perform both overcurrent protection and CCMPFC control for switching circuit Q1 with only single current sensor S3.
FIG. 7 illustrates a parallel converter including: a first converter made up of reactor L1, switching circuit Q1, and diode D1; and a second converter made up of reactor L2, switching circuit Q2, and diode D2, which are connected in parallel. This parallel converter is a multi-phased version of a PFC.